Gold protected reflective coatings

Unprotected gold has high reflectance in the near, mid and far infrared (IR) regions. As gold doesn’t oxidize it does not need to have a protective dielectric overcoat however, bare gold is very soft and easily scratched, and can only be cleaned by flow-washing with solvents, or by blowing the surface clean with a low pressure stream of dry air. Durability is greatly enhanced with a protective overcoat.

Protected gold can be cleaned regularly using standard organic solvents. Gold is chemically unreactive making it well suited to harsh environments. Protected gold offers excellent reflectance from 700nm through mid IR, it is not sensitive to wavelength, angle of incidence or polarization, so it is useful for a wide range of monochromatic and polychromatic applications.
Enhanced gold is over coated with a multilayer dielectric film that is designed to optimise reflectance at a specific wavelength. This coating is recommended for applications involving high power CW lasers, especially when deposited on copper substrates due to the heat dissipation characteristics of copper. This coating is sensitive to wavelength, angle of incidence and polarisation.

For more information or to place an order contact our multilingual technical sales team on +44 (0)1622 859 444 or email us and discover how Knight Optical can improve your instrumentation and supply chain experience.